It is around 2 years old laptop, and in the beginning I was able to use this laptop with TwinView configuration. It worked perfect.
Sometime later during kernel upgrade and nvidia driver upgrades, TwinView broken. I'm sorry, I can't really recollect when really that happened.

Single View still works for me. But I badly want to use my External IBM Monitor at work.

Here's my problem description:

When I start X with the External Monitor connected, the screen goes blank with no message. There is no X display on the external monitor. But X draws an Extended Desktop because on the laptop's display, only half of the virtual desktop is drawn. The External Monitor behaves as if nothing is connected to it.

My first suspect was that the VGA port might have gone bad. But I think that might not be the case. This is how I concluded that:

If the VGA port was bad, X wouldn't have been able to detect the External Monitor. My xorg.conf doesn't have any mention of the external monitor.

I strongly believe this to be a Kernel or nvidia driver problem. That is because I have used this configuration (TwinView) before. I believe it is not a hardware failure.

I can provide you nvidia-bug-report.sh output when I again try connecting the monitor. But please, can you help and work with me on fixing this bug?
TwinView is great, but for me, I've not been able to use it lately.